African American women are more likely than other racial groups to enter pregnancy overweight or obese. Overweight and obese women are more likely to gain excessive weight during pregnancy and retain this weight postpartum than normal weight women, increasing their already high risk for obesity-related comorbidities. Reduced physical activity (PA) and increased dietary intake contribute to this excessive weight gain. Effective behaviorally grounded lifestyle interventions are needed to help pregnant women, especially those who are overweight or obese, of low income, and African American, prevent excessive gestational weight gain and lose weight during postpartum. Thus, the primary goals of the proposed project are to conduct formative work to develop a behavioral intervention (Phase 1) and then test the feasibility of a tailored behavioral intervention to prevent excessive weight gain in pregnancy and promote weight loss in early postpartum among overweight and obese African American women (Phase 2). In Phase 1, interviews will focus on understanding women's perspectives, preferences, barriers, and experiences with weight-related behaviors as well as their preferred channel(s) and intensity of intervention delivery (n=10/group, total 30). In Phase 2, overweight or obese African American women aged 18-39 years in early pregnancy (d15 weeks) will be enrolled from two obstetrical clinics and followed to 12 weeks postpartum. Women will be randomized to the behavioral intervention group or a comparison group (n=20/group, 40 total). Social cognitive theory will inform the behavior change strategies targeted in the intervention, and the content, channel, and intensity of the intervention will be guided by results from Phase 1. The intervention will be delivered beginning within 18 weeks (depending on the timing of enrollment) through 36 weeks gestation and will resume at 6 weeks postpartum through 12 weeks postpartum. Women in the comparison group will receive a comparable number of intervention contacts via print mailings as women in the behavioral intervention group. Primary outcomes will be the rate of average weight gain across the last two trimesters of pregnancy and weight retention at 12 weeks postpartum. Secondary outcomes include PA and diet. The proposed study is innovative because it will use qualitative method to develop a behavioral intervention and then pilot test the intervention to a high-risk, high-need group (i.e., overweight/obese African American women) that has received very little study. PUBLIC HEALTH RELEVANCE: The majority of women enter pregnancy overweight or obese, and this is particularly the case for African American and low income women. These overweight/obese women are at higher risk for pregnancy- associated weight retention after delivery than normal weight women, which further increases their already high risks for obesity-related comorbidities. This proposed theory-based lifestyle intervention will be well- matched to the unique needs and barriers of this high-risk and high-need group, addresses gaps in literature, and will address an important clinical and public health problem.